This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2001-139090, filed May 9, 2001, the entire contents of which are incorporated herein by reference.
1. Field of the Invention
Recently, a liquid crystal display (LCD) apparatus has been put to practical use, which has a reflection display function of displaying an image by reflecting ambient light such as sunlight. In this type of LCD apparatus, in general cases, when an image is displayed by reflection light, the viewing angle is increased by scattering the reflection light. A reflection electrode provided in the LCD apparatus has unevenness on its surface in order to scatter reflection light.
2. Description of the Related Art
A prior-art LCD apparatus having such an uneven surface layer is disclosed in, e.g. Jpn. Pat. Appln. KOKAI Publication No. 2000-258762. According to the LCD apparatus of KOKAI No. 2000-258762, an array substrate has an uneven layer of insulating material as an underlayer of a reflection electrode. The reflection electrode has unevenness corresponding to the unevenness of this uneven layer.
The uneven layer is formed, for example, in the following manner. A positive type photosensitive resin is coated on a substrate. The photosensitive resin is exposed via a predetermined pattern mask, and is subjected to development. Thus, the photosensitive resin with an uneven shape is formed. Subsequently, the developed photosensitive resin is heated by so-called post-baking. Thereby, the photosensitive resin is melted to form the smooth unevenness and is solidified. An uneven layer is thus formed.
When the uneven layer is formed by the method of KOKAI No. 2000-258762, high-temperature heating is effected in solidifying the photosensitive resin. However, due to a steep rise in temperature at the post-baking, the photosensitive resin may excessively be melted. In such a case, it is difficult to form desired unevenness on the photosensitive resin. Consequently, it is disadvantageously difficult to increase the viewing angle in the LCD apparatus having a reflection display function.
The present invention has been made in consideration of the above problems and its object is to provide a liquid crystal display apparatus and a method of manufacturing the same, which realize an increase in the viewing angle without causing non-uniform reflection.
According to a first aspect of the present invention, there is provided a method of manufacturing a liquid crystal display apparatus having a liquid crystal layer between a first substrate and a second substrate and having an uneven layer with an uneven shape on a liquid crystal layer side of the first substrate, wherein the uneven layer is formed by: a layer-forming step of forming a photosensitive resin layer on the first substrate; a first exposure step of exposing the photosensitive resin layer through a mask having a predetermined pattern; a developing step of developing the photosensitive resin layer exposed in the first exposure step; a second exposure step of exposing an entirety of the developed photosensitive resin layer; and a heating step of heating the photosensitive resin exposed in the second exposure step.
According to a second aspect of the present invention, there is provided a liquid crystal display apparatus having a liquid crystal layer between a first substrate and a second substrate, the first substrate having an uneven layer with an uneven shape on a liquid crystal layer side of the first substrate, wherein the uneven layer is formed by: a layer-forming step of forming a photosensitive resin layer on the first substrate; a first exposure step of exposing the photosensitive resin layer through a mask having a predetermined pattern; a developing step of developing the photosensitive resin layer exposed in the first exposure step; a second exposure step of exposing an entirety of the developed photosensitive resin layer; and a heating step of heating the photosensitive resin exposed in the second exposure step.
According to the liquid crystal display apparatus and the method of manufacturing the same, the entirety of the photosensitive resin is exposed in the second exposure step before the photosensitive resin is heated. Thus, the viscosity of the photosensitive resin at the time prior to heating increases. Therefore, excessive melting of the photosensitive resin can be suppressed even when the photosensitive resin is heated in the heating step.
Thus, an uneven shape to be created on the photosensitive resin can easily be controlled and the desired uneven shape can uniformly be formed in accordance with the predetermined pattern of the photomask. Moreover, since the uniform uneven shape can be created, the occurrence of non-uniform reflection can be suppressed and the viewing angle can be increased.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.